by Julia Ryan, USA TODAY

by Julia Ryan, USA TODAY

This week in Tech we took a peek into the finances of a few tech giants, tested a sneaky new mobile security app and said goodbye to some classic video game companies. Here's what you need to know about the week in Tech:

1) Music apps sing a popular song for music stores

Your smartphone and your guitar can exist in perfect harmony. Musical instruments are experiencing a comeback, thanks to YouTube and new tech-enabled music devices.

USA TODAY's Jefferson Graham took a look at the latest musical tech innovations at the National Association of Music Merchants (NAMM) convention earlier this week.

New products include a USB ukulele, a wireless guitar amp and a musical ball that lets you create music.

NAMM CEO Joe Lamond said YouTube has helped spur interest in musical instruction because it has a wide variety of music-lesson videos. Offerings range from amateurs to music stars such as James Taylor and Robben Ford.

Lamond said music apps are "a good start, but there's nothing like live interaction with a teacher." If you want to learn an instrument, tapping on your iPad's keyboard app can only get you so far.

2) Lookout for Android can take a picture of a phone thief

Having your cellphone stolen can be frustrating, but it's even more frustrating -even dangerous - if you store personal information on the phone. A new Android app takes the logic behind the iPhone's "Find My Phone" app one step further with a Lock Cam feature that can take a photo of the person who stole your device.

The Lookout app takes a photo of the thief silently using the phone's front-facing camera and e-mails you a photo and a location of where the phone is.

USA TODAY's Ed Baig tried out the app on a Google Nexus 4 smartphone and said he "came away pleased" with the Lookout's many security tools. But he noted that a few key features, such as the ability to remotely lock or wipe your smartphone and the option to display a message telling the finder how to return your phone, are only available to premium users.

Our take: If you're a heavy phone user, or if you use an Android smartphone for work, spring for the premium plan. At $2.99 a month, it's a small price to pay for some peace of mind.

3) The week in Tech earnings

Apple, Google and Microsoft all released earnings reports this week, giving investors and tech experts a good sense of what the tech world will be like this year.

Here's how each company fared:

â?¢ Google - better than expected: Google took in $2.89 billion in the fourth quarter ($8.62 a share), up from $2.71 billion last year ($8.22 a share). Google also reported revenue of $11.34 billion, up from $8.13 billion a year ago.

â?¢ Apple - worse than expected: Apple missed analysts' iPhone sales forecasts for the holiday shopping season. The company reported a profit of $13.1 billion for its fiscal first quarter ($13.81 a share), compared with a profit of $13.1 billion this time last year ($13.87 a share). The company's revenue guidance for the current quarter is between $41 billion and $43 billion, slightly below expectations of $45 billion.

â?¢ Microsoft - mixed: The company said its net income fell 4% to $6.38 billion (76 cents a share) compared with a year ago, but its revenue rose 3% to a record $21.46 billion.

4) Bankruptcy for Atari, THQ dissolves assets

It's the end of an era in the video game world this week. The U.S. division of Atari filed for bankruptcy protection on Monday after 40 years of video game production, moving to separate from its French parent company.

Atari gained a huge following in the '70s and '80s with popular games such Pong and Centipede, and has attempted a rebound by re-releasing its classic titles on mobile platforms.

THQ fell from the ranks of video game publishers after a judge cleared plans to sell its assets, many of which were acquired by competitors. Among the higher-profile acquisitions: Koch Media snagged the rights to the Saints Row series, while Sega scooped up the developers of the strategy franchise Company of Heroes.

5) Surface Windows 8 pro tablet to launch Feb. 9

Microsoft announced on Tuesday that the Surface Windows 8 Pro tablet will be released on Feb. 9 starting at $899.

The Pro tablet is an expanded version of the previously released Surface tablet, with options for using the device as a tablet or a laptop and an optional "Touch Cover."

Be sure to check back with Tech next month for a full review from Ed Baig.